Some image forming apparatuses are provided with replacement parts to store consumables. Such replacement parts include a toner cartridge to contain a toner (a developer). The toner cartridge is packaged in a packaging box via a buffering member in order to prevent the toner from being ejected or the toner cartridge from being damaged when the toner cartridge is applied with an impact or dropped during storage or transportation. The packaging box or the buffering member to package the toner cartridge which is one of the replacement parts is required to be formed of a minimum number of components and then to minimize an increase in cost.
In Patent Document 1 or Patent Document 2, there is proposed a buffering structure in which buffering members each formed by folding a corrugated cardboard into a rectangular cylindrical shape are oppositely disposed inside of the packaging box, and via the buffering members, a packed article is packaged.